For this step and the next, you may want to pretend you are K1JT
by entering that callsign temporarily as *My Call* on the 
*Settings | General* tab.  Your results should then be identical to
those shown in the screen shot below.

.Open a Wave File:

- Select *File | Open* and select the file
+...\save\samples\JT9\130418_1742.wav+. When the file opens you should
see something similar to the following screen shot:

[[X12]]
image::main-ui.png[align="center",alt="Main UI and Wide Graph"]

.Decoding Overview

Decoding takes place at the end of a receive sequence and proceeds in
two steps.  The first decode is done at the selected Rx frequency,
indicated by the U-shaped green marker on the waterfall scale.
Results appear in both the left (*Band Activity*) and right (*Rx
Frequency*) text windows on the main screen. The program then finds
and decodes all signals in the selected mode over the displayed
frequency range. The red marker on the waterfall scale indicates your
Tx frequency.

Seven JT9 signals are present in the example file, all decodable.
When this file was recorded KF4RWA was finishing a QSO with K1JT.
Since the green marker was placed at his audio frequency, 1224 Hz, his
message `K1JT KF4RWA 73` is decoded first and appears in the *Rx
Frequency* window. The *Band Activity* window shows this message plus
all decodes at other frequencies.  By default lines containing `CQ`
are highlighted in green, and lines with *My Call* (in this case K1JT)
in red.

[[X13]]
.Decoding Controls

To gain some feeling for controls frequently used when making QSOs,
try clicking with the mouse on the decoded text lines and on the
waterfall spectral display. You should be able to confirm the
following behavior:

- Double-click on either of the decoded lines highlighted in
green. This action produces the following results:

** Callsign and locator of a station calling CQ are copied to the *DX
Call* and *DX Grid* entry fields.

** Messages are generated for a standard minimal QSO.

** The *Tx even* box is checked or cleared appropriately, so that you
will transmit in the proper (odd or even) minutes.

** The Rx and Tx frequency markers are moved to the frequency of the
CQing station.

** The *Gen Msg* ("`generated message`") radio button at bottom right 
of the main window is selected.

** If you had checked *Double-click on call sets Tx Enable* on the
*Setup* menu, *Enable Tx* would be activated and a transmission would
start automatically at the proper time.

- Double-click on the decoded message `K1JT N5KDV EM41`,
highlighted in red.  Results will be similar to those in the
previous step, except the Tx frequency (red marker) is not
moved.  Such messages are usually in response to your own CQ, or from
a tail-ender, and you probably want your Tx frequency to stay where it
was.

- By holding down the *Ctrl* key when double-clicking on a decoded
line you can cause both Tx and Rx frequencies to be moved.  This
behavior can also be forced by checking *Lock Tx=Rx*.

- Double-click on the message from KF4RWA in either window. He is
sending `73` to K1JT, signifying that the QSO is over.  Most likely
you want to send 73 to him, so the message `KF4RWA K1JT 73` is
automatically generated and selected for your next transmission.
(Alternatively, you might choose to send a free-text message or to
call CQ again.)

- Click somewhere on the waterfall to set Rx frequency (green marker
on waterfall scale).

- Shift-click on the waterfall to set Tx frequency (red marker).

- Ctrl-click on the waterfall to set both Rx and Tx frequencies.

- Double-click on a signal in the waterfall to set Rx frequency and
start a narrow-band decode there. Decoded text will appear in the
right window only.

- Ctrl-double-click on a signal to set both Rx and Tx frequencies and
decode at the new frequency.

- Click *Erase* to clear the right window. 

- Double-click *Erase* to clear both text windows.
